Fass pressure spring change

[tractorface]

I want to lower my fuel pressure from the FASS tomorrow. I have the new spring, trouble is I do not know where it goes. Anyone do this and offer up some basic instructions. I just need to know where the spring goes. Am getting 18psi up from 16 psi since my custome fuel module install. Spikes to 21 psi when it is real cold out. Takes 30 miutes or so to warm up and come back down to 18 psi. Was told that the spring I got wil reduce pressure by about 6 psi which should be perfect. Also was told there is a place on the FASS for my low prssure switch. Anyone know where tis is? I have an old unit bought around Thanksgiving 03.

Thanks in advance

 

[Oil Burner]

I'm not sure if our pumps are the same, but I believe you take the four nuts loose on the end of the pump. then slide the aluminum block off along with a gasket and inside is a ball and spring. The spring is what you want to swap, then put it back together.



Hope this helps????



are you worried your pressures are too high?



Thanks,

Jason

 

[tractorface]

thanks

I just do't see any reason to keep them that high.

 

[Oil Burner]

I have a spring to change also. but I'm looking for more pressure (11. 5 at idle) and was just wondering if DPP had advised you NOT to run that high of a pressure. I might try to relieve that spring or stretch the one I have now if the new one idles too high.



Thanks,

Jason

 

[pgleavitt]

Looking at the Fass,you want the hose that has a swivel fitting on the end of the hose. It will be on the front of the fass on the end that points towards the engine. Un-screw the hose fitting to remove the hose and then remove the fitting that goes into the fass body. The spring is behind this fitting. Watch out as the metal ball may also fall out. Make sure the ball goes in and than the spring. Replace the fitting into the body and hook up the hose. Clean up the diesel that drained to your armpit and bump the starter to remove the air. This took me longer to type than it takes to change out the spring. Instructions are for the fass with filters, not the stand alone pump.

 

[tractorface]

Thanks that is what I was thinking but was not sure. Everything I have read leads me to believe that a steady 10 psi or so is ideal. No need to test the theory that to high a pressure will accelerate VP wear as well as make the FASS work harder. Also lower psi means less chance of leaks.

 

[tractorface]

Real easy deal

Spring right behind Return line just like you told me. Real easy job. Running a steady 13psi and goes no lower than 11 psi